12209531378 has 18 divisors (see below), whose sum is σ = 20133425487. Its totient is φ = 5549005660.

The previous prime is 12209531357. The next prime is 12209531387. The reversal of 12209531378 is 87313590221.

It can be written as a sum of positive squares in only one way, i.e., 6104765689 + 6104765689 = 78133^2 + 78133^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=78133.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1715375 + ... + 1722477.

Almost surely, 2^12209531378 is an apocalyptic number.

12209531378 is a deficient number, since it is larger than the sum of its proper divisors (7923894109).

12209531378 is an frugal number, since it uses more digits than its factorization.

12209531378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14230 (or 7116 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 41.

The spelling of 12209531378 in words is "twelve billion, two hundred nine million, five hundred thirty-one thousand, three hundred seventy-eight".